Conventionally, a computer system comprises a computer device, a mouse, a keyboard, a monitor, a speaker and a video apparatus. In general, the mouse, the keyboard, the monitor, the speaker and the video apparatus are referred to as console devices that are used for controlling the computer device or controlled by the computer device. A computer switch is provided among various console devices and plural computer devices. The computer switch selects one of the plural computer devices so that the console devices may control the selected computer device and output instructions to the selected computer device or input the response from the selected computer device. Moreover, there is provided a universal serial bus (referred to as USB hereinafter) hub port on the computer switch for connecting USB devices. The USB devices on the computer switch, however, only control one of the plural computer devices or are controlled by one of the computer devices. In other words, the USB devices do not have the controlling functions of controlling the plural computer device and switching as the console devices. Referring to FIG. 3, it illustrates a computer switch of prior art. The conventional computer switch 300 includes a USB hub port interface 301 for connecting one or more external USB devices 301-1 to 301-4, such as hard drives, mice, keyboards, printers, etc.; a console port interface 302 for connecting one or more console devices 302-1 to 302-2; a matrix switching circuit 303 connected to plural computer interfaces 305 (N computer interfaces in FIG. 3), the USB hub port interface 301 and the console port interface 302; and a main controlling circuit connected to the plural computer interfaces 305 and the matrix switching circuit 303. The computer interfaces 305 connect to a computer device such as a personal computer, a notebook, a smart phone and a personal digital assistant (PDA) (not shown in FIG. 3) respectively. As can be seen from FIG. 3, the console devices 302-1 to 302-2 connect to the main controlling circuit 304 through the console port switching interface 3031 in the matrix switching circuit 303 so as to control plural computer interfaces 305. In contrast, the USB devices 301-1 to 301-4 connect to and transmit signals to one of the N computer interfaces 305 respectively through the matrix switching circuit 303 or are controlled by the computer device to which the selected computer interface 305 is connected. For example, in FIG. 3, USB device 301-1 connects to the first computer interface 305 through the matrix switching circuit 303; USB device 301-2 connects to the second computer interface 305 through the matrix switching circuit 303. Further, the matrix switching circuit 303 determines the connecting relationship between the USB devices 301-1 to 301-4 and the computer interfaces 305.
Apparently, the above construction doesn't meet various conditions or special operational needs. This is because that the USB devices 301-1 to 301-4 connected to the USB hub port interface 301 only has a hub function, not a controlling function such as instructing each computer interface 305, switching among the computer interfaces 305, etc. When the computer switch 300 and the console devices 302-1 to 302-2 connected to the console port interface 302 are provided in different places, the problem is more troublesome. For example, when the computer switch 300 is provided in the machine room and the console devices 302-1 to 302-2 are provided in the control room, the user can't control and switch the unconnected computer interfaces 305 via the proximate USB devices 301-1 to 301-4. The user switches and controls the unconnected computer interfaces 305 only by the console devices 302-1 to 302-2. Thus the need rises in maintenance and special operational environment.